Gas dishwasher venting and heating arrangement



Nov. 26, 1963 J. CLAYWELL 3,111,941

GAS DISHWASHER VENTING AND HEATING ARRANGEMENT Filed on. 9, l96l 2 Sheets-She et 1 Nov. 26, 1963 J. w. CLAYWELL 3,111,941

GAS DISHWASHER VENTING AND HEATING ARRANGEMENT Filed Oct. 9, 1961 2 Sheets-Sheet 2 United States Patent 3,111,941 GAS DISHWASIER VENTING AND HEATING ARRANGEMENT Jack W. Claywell, Wisconsin Rapids, Wis., assignor to Preway Inc, a corporation of Wisconsin Filed Oct. 9, 1961, Ser. No. 143,737 11 Claims. (Cl. 126-345) This invention relates to the venting of combustion gases from an article washing apparatus utilizing gas and, more particularly, to the venting of combustion gases from a gas dishwasher.

An object of this invention is to provide a new and improved article washing apparatus in which a gas burner is used to heat water with means for diluting and cooling combustion gases prior to venting thereof from the article washing apparatus.

In a gas burning appliance, the exhaustion of combustion gases is normally to the outside of a home or the like. Such operation requires the connection of the appliance to a line pipe. It is desirable to avoid this requirement and by means of the invention disclosed herein it is possible to vent combustion gases back to the room. Due to the high temperature of these gases, such operation would not normally be thought possible; however, by the apparatus disclosed herein the combustion gases are thoroughly diluted with room air which renders the gases non-objectionable and which reduces the temperature thereof to a level sufiicient for safe venting into the room.

Accordingly, another object of the invention is to provide a gas dishwasher with means for heating water in the tub including a heat exchange tube passing adjacent the bottom thereof with a gas burner at one end of the tube and an opposite end of the tube extending into a generally horizontal conduit beneath the tub, and means connected to the conduit for passing outside air through the conduit to mix with and dilute the combustion gases passing from the tube.

A further object of the invention is to provide a gas dishwasher as defined in the preceding paragraph in which means are provided in association with the c0nduit for adding additional external air to the combustion gases in response to the flow of gases through the conduit.

Further objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIG. 1 is a perspective elevation-a1 view of a gas dishwasher embodying the invention and having the door of the dishwasher open to show the interior thereof;

FIG. 2 is a horizontal section on an enlarged scale taken generally along the line 22 in FIG. 1;

PEG. 3 is a vertical section taken generally along the line 3-3 in FIG. 2; and

FIG. 4 is a view similar to FIG. 3 showing an alternate connection for venting combustion gases to the exterior.

While this invention is susceptible of embodiment in many different forms there is shown in the drawings and Will herein be described in detail an embodiment of the invention together with a modification thereof with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

As shown in FIG. 1, the article washing apparatus is disclosed in the form of a gas dishwasher in which the cabinet 1% has an interior tub with a door 11 and a tub bottom 12 with a centrally located sump 13 in which 3,1 1 1,941 Patented Nov. 26, 1963 water is collected for heating thereof as part of the cycle of operation of the dishwasher. Water is circulated Within the dishwasher by means of a pair of spray arms, one of which is shown at 14, which are located on the opposite sides of the interior and which are caused to rotate about a horizontal axis by the flow of water therefrom. Water is supplied to the spray arms from the sump through a sump outlet 15 which is connected to a pump 16 driven by a motor 17 with the pump having an outlet 18 which, through pipes (not shown), connects t0 the spray arms.

In order to drain water from the tub, the central drain outlet 26 connects to a motor driven pump 21 having an outlet 22 leading to a drain connection. The foregoing structure is generally shown in my copending application, Serial No. 28,895, filed May 13, 1960, and reference may be had thereto for a more detailed description of the foregoing structure.

For heating of water in the sump, a heat exchange tube 25 extends lengthwise therethrough with a gas burner 39 located at one end thereof which is supplied with air under pressure from a blower 31 driven by a motor 32, and which may be of a type disclosed in the copending application of I. W. Claywell and C. J. Pavlalc, Serial No. 143,736, filed October 9, 1961. As disclosed in the referred to application, ignition of the gas is effected by ignition means which, as shown, is in the form of a spark plug 33 connected into a suitable electric circuit. The burner operates in a manner to substantially eliminate the production of carbon monoxide gas.

In order to vent the combustion gases passing through the heat exchange tube 25, means are provided as shown in FIGS. 1, 2 and 3 embodying a conduit having an elbow of a generally rectangular cross section which receives an open end 41 of the heat exchange tube. Air under pressure is caused to flow through the conduit by an air blower 42 driven by a motor 43 connected to an end of the elbow and having an inlet receiving air from the space adjacent the dishwasher. The conduit 49 extends generally horizontaily beneath the tub and has an outlet 45 opening toward the front of the dishwasher.

L1 the embodiment shown in FIGS. 1 to 3, a second hornshaped conduit 46 is associated with the first conduit and is generally rectangular in cross section with an inlet end 47 thereof overlapping the outlet end 45'of the conduit it). The conduit 46 is supported by attachmerit to the conduit 49 by screws at the top and bottom as indicated at 43 and 49 in FIG. 3 and at the front end thereof by attachment to a strap 56 extending between a base 51 of the dishwasher and the tub bottom 12. The sides of the inlet of the second conduit 46 are spaced from the adjacent side walls of the first conduit outlet 45 as indicated at 52 and 53 to form a throat, whereby additional air may be drawn into the second conduit 46 as induced by the velocity of the air and combustion gas mixture passing from the first conduit to the second conduit. The second conduit has an outlet 55 terminating behind a suitable apertured front panel 56 for the dishwasher and the second conduit due to its horn-shape opens to an extremely large outlet whereby the velocity of the combustion gas and air mixture is substantially reduced to avoid high velocity flow of the mixture out through the front panel 56 of the dishwasher.

As is clearly seen in FIGS. 2 and 3, the first conduit 44 is formed by a top wall 60 and a bot-tom wall 61 connected by a rear wall 62 and a front wall 63 and the second conduit 46 is formed by a top wall 64 and a bottom wall 65 connected by side walls 66 and 67.

In addition to cooling and diluting the combustion gases passing out of the heat exchange tube 25, the

3 flow of air therepast tends to provide a draft effect in the heat exchange tube due to the end 4-1 of the heat exchange tube being shaped on a bias to the longitudinal extent thereof whereby the outlet opens in a direction downstream of the air fiow through the vent conduit 49.

The basic construction shown in FIGS. 1, 2 and 3 permits of alternate connection for venting of the combustion gases to the outside as shown in FIG. 4. A pipe 70 is connected to the outlet end 45 of the conduit 40 and the pipe has a U-shaped bend therein to extend to the rear of the dishwasher and beyond the back thereof for connection to a flexible tube 71 or the like which extends to a suitable connection to the outside. The pipe 70 is connected to the conduit 40 in a manner similar to that shown in FIGS. 1 to 3 by means such as screws 75 and 76.

With the foregoing construction, it will be seen that the combustion gases are diluted and cooled by positive means in the form of external air positively directed to a point of mixture with the combustion gases discharged from the heat exchange tube 25. Additionally in the form of FIGS. 1 to 3, the velocity of the aforesaid mixture is used to draw in additional air for further cooling and dilution. The velocity of this mixture is then reduced before venting out the front panel of the dishwasher by the enlarged outlet end of the conduit formed by the horn-shape thereof.

Iclaim:

1. An article washing apparatus comprising, a tub, means for circulating water in the tub, means for heating water in the tub including a heat exchange and combustion tube adjacent the bottom of the tub and a gas burner associated with the tube, and !II163I1S for venting exhaust gases into the surrounding area comprising, an exhaust gas passage to which said tube connects, means for directing air under pressure into said passage upstream of said tube, and means providing for drawing of additional downstream air into said passage by the velocity of said air under pressure, said passage terminating at the front of said apparatus.

2. An article washing apparatus comprising, a tub, means for circulating water in the tub, means for heating water in the tub including a heat exchange and combustion tube adjacent the bottom of the tub, a gas burner associated with one end of the tube and the other end of the tube being open, and means for exhausting combustion gases from the apparatus comprising, a conduit for combustion gases in which said tube open end is located, said tube and conduit being angularly related,

and an air blower connected to said conduit upstream of said tube open end for causing air to flow through said conduit across the tube open end to draw and mix with the combustion gases prior to venting thereof from the apparatus.

3. An article washing apparatus as defined in claim 2 in which an additional conduit forms a continuation of the first conduit and extends to the front of the apparatus for venting of the gas and air mixture at said front.

4. An article washing apparatus as defined in claim 3 in which said conduits at their junction are spaced apart to permit drawing in of additional air as induced by flow through the conduits.

5. An article washing apparatus as defined in claim 2 in which a flue pipe is connected to said conduit for outside discharge of combustion gases.

6. In a gas dishwasher having a tub with a centrally depressed sump at the bottom thereof, means for heating water in the sump including a heat exchange and combustion tube passing therethrough, a gas burner at one end of said tube, an opposite end of the tube extending beyond the sump, a combustion gas passage including a generally horizontal conduit beneath the tub and to the side of the sump receiving said opposite end of the tube and opening toward the front of the dishwasher, said tube being positioned at an angle to said conduit, an air blower connected to said conduit for moving external air past said opposite end of the tube and directing com-bustion gases and air toward the front of the dishwasher.

7. A gas dishwasher as defined in claim 6 having means downstream of said tube opposite end for adding additional external air to the combustion gases in response to flow of gases through the conduit.

8. A gas dishwasher as defined in claim 6 in which said conduit terminates in an outlet, and a second conduit extending from the first conduit toward the front of the dishwasher to vent gases to said front, said second conduit having an inlet surrounding the outlet of the first conduit with parts in spaced relation to permit entry of air to the second conduit as induced by reduced pressure within the conduit, and said second conduit flaring from the inlet to the outlet to provide an outlet of a size substantiaily larger than the inlet.

9. A gas dishwasher as defined in claim 8 in which said second conduit inlet overlaps the first conduit outlet to create a throat through which induced air may pass into said second conduit.

10. A gas dishwasher as defined in claim 6 in which said opposite end of the heat exchange tube is shaped on a bias relative to the length thereof and opens in a downstream direction relative to air flow through said conduit whereby the air flow gives a draft effect in the heat exchange tube.

11. A gas dishwasher as defined in claim 6 in which said gas passage enlarges toward its outlet to reduce the velocity of gas passing therethrough before discharge.

References Cited in the file of this patent UNITED STATES PATENTS 229,776 Robertson et al. Nov. 3, 1885 369,131 Smith et a1 Aug. 30, 1887 533,129 Kabat et a1. Jan. 29, 1895 803,097 De Laney Oct. 31, 1905 1,533,898 Prat Apr. 14, 1925 1,547,156 Loepsinger July 21, 1925 1,851,002 Davis Mar. 29, 1932 2,188,133 Hepburn Jan. 23, 1940 2,621,666 Hiort Dec. 16, 1952 2,825,349 Keliher et al. Mar. 4, 1958 2,841,136 Pettit et al. July 1, 1958 FOREIGN PATENTS 822,509 France Dec. 31, 1937 885,509 Germany Aug. 6, 1953 902,115 Germany Jan. 18, 1954 

1. AN ARTICLE WASHING APPARATUS COMPRISING, A TUB, MEANS FOR CIRCULATING WATER IN THE TUB, MEANS FOR HEATING WATER IN THE TUB INCLUDING A HEAT EXCHANGE AND COMBUSTION TUBE ADJACENT THE BOTTOM OF THE TUB AND A GAS BURNER ASSOCIATED WITH THE TUBE, AND MEANS FOR VENTING EXHAUST GASES INTO THE SURROUNDING AREA COMPRISING, AN EXHAUST GAS PASSAGE TO WHICH SAID TUBE CONNECTS, MEANS FOR DIRECTING AIR UNDER PRESSURE INTO SAID PASSAGE UPSTREAM OF SAID TUBE, AND MEANS PROVIDING FOR DRAWING 